Dental disease is today the most common of all human diseases worldwide. An enormous proportion of the American population suffers from dental caries (tooth decay or cavities) and periodontal (gum and bone) disease. Dental caries are virtually ubiquitous: they begin soon after teeth erupt and increase in prevalence with age. The most recent survey, conducted in 1986-7, showed that the average school-aged child has at least one cavity in permanent teeth by age 9 and 8 by age 17. Approximately one in four schoolchildren has five or more decayed, filled, or missing teeth. The average American adult has 10-17 decayed, filled or missing teeth. Furthermore, periodontal diseases are the most prevalent chronic diseases affecting children, adolescents, adults and the elderly. Approximately half of all adults in the U.S. have gingivitis (inflammation of the gums), the first stage of gum disease, and 80% have had some degree of gum inflammation that has led to the destruction of the bone which supports the teeth (periodontitis), which, as if it progresses can lead to tooth loss. Gingivitis was observed in approximately 60 percent of children, while 95% of the elderly have periodontitis. Over half of all adults over age 65 are toothless. In 1989, in the U.S., dental disease caused 51 million hours of missed school, 164 million hours of missed work and 41 million days of restricted activity. Dental expenditures in the U.S. in 1990 were over $30 billion. (U.S. Preventive Services Task Force, Guide to Clinical Preventive Services, Second Edition, 1996) In addition recent research indicates a high correlation between periodontal disease and cardiovascular disease, heart attack, stroke and low-birthweight babies.
Dental plaque is a gelatinous mass or film of bacteria within a matrix of food particles and other organic materials such as mucins. It adheres to and builds up on the surfaces of teeth and is a major cause of both dental caries and periodontal disease. Prevention of dental disease involves oral hygiene practices. Good oral hygiene includes the effective and complete removal of substantially all plaque. Plaque that remains on the teeth calcifies to form calculus or tartar. It is important to remove plaque before it calcifies into calculus that requires more extensive care for its removal, usually by a dental health professional.
Personal oral hygiene practices such as toothbrushing and flossing can prevent the development and progression of periodontal disease by removing plaque. Professional dental care alone is inadequate to prevent periodontal disease. The single most important tool for preventing dental disease is the toothbrush. In the absence of personal plaque removal, after 10 to 21 days, gingivitis develops in healthy adults. This provides strong evidence for the recommendations for at least daily toothbrushing. Other studies confirmed that effective plaque removal every 48 hours was associated with gingival health. The efficacy of personal oral hygiene measures though is dependent upon the ability of the patient to do them effectively, that is to keep the teeth adequately plaque-free. Due to the difficulty many patients have in adopting and maintaining good oral hygiene habits these measures often fail to remove plaque adequately and prevent gum disease. (U.S. Preventive Services Task Force, Guide to Clinical Preventive Services, Second Edition, 1996, and Ismail, A. I., Lewis, D. W., Dingle, J. L. Prevention of Periodontal Disease, in Canadian Guide to Clinical Preventive Health Care, Ottawa: Health Canada, 1994; 420-431). It is important that the patient continue to be motivated to maintain oral hygiene habits. It is important for oral health professionals to counsel patients about the importance of oral hygiene habits and to instruct them in the guidelines for proper effective toothbrushing.
It is also often difficult for the patient to ensure that plaque removal is complete because the patient cannot easily determine (either visually or otherwise) whether all the plaque has been removed. Plaque is translucent or tooth-colored and not therefore visible. This problem can be surmounted through the use of a dental hygiene device which incorporates, for instance, an oral compbsition comprising chemical disclosing agents.
These chemical agents have been used for over 80 years and generally consist of a dye that stains only the plaque and renders it visible in contrast to other oral structures. Chemical disclosing agents come in a variety of forms including solutions that can be topically applied by dental personnel or with which the patient rinses, as well as chewable tablets, lozenges, wafers and powders. A variety of substances have been used as chemical disclosing agents including iodine, basic fuchsin neutral red, erythrosine (e.g., FDC Red No. 3), and others. Some dyes used in the past have had a number of limitations including that they were suspected carcinogens, appeared in the urine or had an unpleasant taste. An appropriate dye should not be long lasting, should be easily removed and should not stain the skin or mucosa to any significant extent. It should not only have a pleasing shade but also allow for effective contrast with surrounding oral tissues. Some dental health professionals feel that a minor drawback to the use of the popular FDC Red No. 3 is that it has poor contrast with oral tissues such as the gingivae. Brown dyes have an unappealing appearance and have been found to be distasteful to users. Some disclosing agents are mixtures of two dyes that further reveal the age and thickness of the plaque. Such an agent is taught in U.S. Pat. No. 3,723,613. The agents disclosed are mixtures of dyes such as FDC Red No. 3 and either FDC Blue No. 1, FDC Green No. 3 or Hercules Green Shade 3. These allow for the differential staining of thin and thick plaque, whereby the thin plaque is stained red and the thicker blue or green.
Patients are usually instructed to brush their teeth in their usual manner and then disclose any remaining plaque through use of the chemical disclosing agent. Then they can brush again until all the stained areas of plaque have been removed. Use of chemical disclosing agents is very effective also for counseling and educating patients in the proper techniques for brushing and plaque removal and for motivating patients to maintain their oral hygiene habits. In British Patent No. 2019215 to Frysh it is taught that a chemical disclosing agent may be included in a dentifrice or toothpaste. The chemical disclosing agent in the Frysh patent includes mixtures of dye that result in the plaque being disclosed as a green color, and the preferred agent was formed by a mixture of Sulphan Blue and Tartrazine Yellow. A plaque disclosing dentifrice containing a mixture of dyes is also taught in U.S. Pat. No. 4,459,277 and in U.S. Pat. No. 5,862,559.
It has been recognized that proper oral hygiene habits are often neglected. Reasons for this include that it is often perceived as time consuming and inconvenient. It requires storing, carrying, ending and having available both toothbrush and dentifrice (toothpaste). For these reasons the prior art is crowded with many descriptions of toothbrush devices which store and dispense toothpaste in an attempt to address these problems. Several are also adapted to dispense other oral hygiene products such as dental floss. Known prior art combination toothpaste dispensing toothbrushes include U.S. Pat. No. 4,865,481, U.S. Pat. No. 5,827,001, U.S. Pat. No. 5,832,940, U.S. Pat. No. 5,911,532, U.S. Pat. No. 5,915,868, U.S. Pat. No. 5,921,692, U.S. Pat. No. 6,027,273, U.S. Pat. No. 6,056,466, U.S. Pat. No. 6,050,736, U.S. Pat. No. 6,056,469, and U.S. Pat. No. 6,095,710. The devices heretofore devised are known to consist basically of familiar, expected and obvious structural configurations, notwithstanding the myriad of designs encompassed by the crowded prior art which have been developed for the fulfillment of countless objectives and requirements. There are fine differences among them employed to distinguish the inventions from one another and to overcome associated problems. Because toothpaste is a viscous substance, most have specialized dispensing mechanisms such as screw driven pistons suitable for delivering this type of substance. All deliver the dentifrice onto the brushhead and bristles. Other individualized features relate to whether the toothbrush is meant to be of limited use and economically disposable or alternatively refillable and reusable. Many of these toothbrushes suffer from disadvantages including that they have complex mechanical features, do not resemble a conventional toothbrush, and are meant for only single or very limited number of uses.
Using a chemical disclosing agent is also inconvenient for the individual as the separate container of disclosing agent must be stored, found and used. One toothbrush device designed for dispensing a chemical disclosing agent is described in U.S. Pat. No. 4,543,679 to Rosofsky et al. The device of Rosofsky et al. is a toothbrush wherein an oral hygiene device can be attached to the tail end of the handle. The oral hygiene devices taught by Rosofsky et al. include a porous pad, which can hold a chemical disclosing agent, or a reservoir that can hold a dry powder or solid form of a chemical disclosing agent. This device does not hold a solution of disclosing agent and is not useful for convenient multiple applications without re-immersion of the pad in the agent.
Applicator devices with simple mechanical systems for applying oral composition are disclosed for example in US 2005/0232686 (Zeh et al). The devices of Zeh et al. include a disposable flexible container configured to hold an oral composition and an applicator tip member couple to the open end of the container used for dispensing the composition. The composition is flown from the flexible container to the head of the applicator member by applying a simple pressure on the side of the container, thereby conveying the oral composition to the open end of the head.
A further device of relevance is taught in U.S. Pat. No. 6,371,674 to Lerner, which is hereby incorporated by reference in its entirety. The Lerner device is a toothbrush with storage and dispensing arrangement for plaque disclosing solution which releases drops of the solution from the rear side of the toothbrush head.
The aforementioned devices suffer from a number of shortcomings. Firstly, chemical disclosing agents are, by their very nature, strongly colored dyes which cause unwelcome staining if they fall on skin tissue or other objects unintentionally, and may even cause damage to clothing or other objects onto which it falls. It has been found that the dispensing arrangements of Rosofsky et al. and Lerner do not provide sufficient precision of application of the chemical disclosing agent to avoid the aforementioned soiling.
Furthermore, particularly with reference to the Lerner device, it is noted that the head of the toothbrush is a region exposed to immersion in saliva and toothpaste during normal use of the toothbrush, and is therefore prone to blockage. It would also be considered advantageous from the point of view of hygiene if the disclosing agent dispensing mechanism was a non-contact dispensing mechanism which did not need to contact tissue surfaces within the mouth during application of the disclosing agent.
Finally, reference is also made to WO2007/049298 and WO2007/020660 which both teach a toothbrush with a spray dispenser for dentifrice and the like located beneath the bristles of the toothbrush head. Here too, the spray dispenser is at risk of becoming blocked due to repeated exposure to saliva and toothpaste. It is also likely that at least part of the spray will fall on the bristles themselves, causing soiling of the bristles, possible dripping of excess liquid from the bristles, and consequent wastage of the liquid sprayed.
It is therefore an object of the invention to provide a toothbrush comprising a dental hygiene device for disclosing oral microbes, which overcomes the above-mentioned shortcomings of the prior art devices.
It is a further object of the invention to provide a toothbrush comprising a dental hygiene device, which enables a precise application of the microbe disclosing agents.
It is another object of the invention to provide a toothbrush comprising a dental hygiene device for disclosing and treating dental diseases.
It is still another object of the present invention to provide a toothbrush comprising several dental hygiene devices, each of these devices being able to prkisely deliver disclosing or treating agents.
Other objects and advantages of the present invention will appear as the description proceeds.